[FIX] purchase: use the current company currency in purchase analysis

Steps to reproduce the bug:
- Connect with a company using USD currency.
- Create a storable product "P1":
    - Cost: $100

- Create a Purchase order:
    - Add 1 unit of "P1"
    - Currency: USD

- Create another Purchase order:
    - Add 1 unit of "P1"
    - Currency: EUR

- Go to the purchase analysis and select the list view.

Problem:
The purchase order in EUR is converted into the current company
currency, but the Euro currency symbol is used instead of the dollar
symbol

opw-3354221
opw-3348265

closes odoo/odoo#127389

Signed-off-by: William Henrotin (whe) <whe@odoo.com>

addons/purchase/report/purchase_report.py

@@ -80,7 +80,7 @@ class PurchaseReport(models.Model):
                     l.product_id,
                     p.product_tmpl_id,
                     t.categ_id as category_id,
-                    po.currency_id,
+                    c.currency_id,
                     t.uom_id as product_uom,
                     extract(epoch from age(po.date_approve,po.date_order))/(24*60*60)::decimal(16,2) as delay,
                     extract(epoch from age(l.date_planned,po.date_order))/(24*60*60)::decimal(16,2) as delay_pass,
@@ -111,6 +111,7 @@ class PurchaseReport(models.Model):
                 join res_partner partner on po.partner_id = partner.id
                     left join product_product p on (l.product_id=p.id)
                         left join product_template t on (p.product_tmpl_id=t.id)
+                left join res_company C ON C.id = po.company_id
                 left join uom_uom line_uom on (line_uom.id=l.product_uom)
                 left join uom_uom product_uom on (product_uom.id=t.uom_id)
                 left join account_analytic_account analytic_account on (l.account_analytic_id = analytic_account.id)
@@ -133,7 +134,7 @@ class PurchaseReport(models.Model):
                 po.user_id,
                 po.partner_id,
                 line_uom.factor,
-                po.currency_id,
+                c.currency_id,
                 l.price_unit,
                 po.date_approve,
                 l.date_planned,

addons/purchase/tests/test_purchase_order_report.py

@@ -153,3 +153,35 @@ class TestPurchaseOrderReport(AccountTestInvoicingCommon):
         )
         self.assertEqual(report[0]['qty_ordered'], 11)
         self.assertEqual(round(report[0]['price_average'], 2), 46.36)
+
+    def test_po_report_currency(self):
+        """
+            Check that the currency of the report is the one of the current company
+        """
+        po = self.env['purchase.order'].create({
+            'partner_id': self.partner_a.id,
+            'currency_id': self.currency_data['currency'].id,
+            'order_line': [
+                (0, 0, {
+                    'product_id': self.product_a.id,
+                    'product_qty': 10.0,
+                    'price_unit': 50.0,
+                }),
+            ],
+        })
+        po_2 = self.env['purchase.order'].create({
+            'partner_id': self.partner_a.id,
+            'currency_id': self.env['res.currency'].search([('name', '=', 'EUR')], limit=1).id,
+            'order_line': [
+                (0, 0, {
+                    'product_id': self.product_a.id,
+                    'product_qty': 10.0,
+                    'price_unit': 50.0,
+                }),
+            ],
+        })
+        # flush the POs to make sure the report is up to date
+        po.flush()
+        po_2.flush()
+        report = self.env['purchase.report'].search([('product_id', "=", self.product_a.id)])
+        self.assertEqual(report.currency_id, self.env.company.currency_id)